The incredible success and rapid growth of the Internet has understandably generated a demand for ever-increasing bandwidth in accessing information on the Internet. As a result, ISDN equipment has become very attractive to many people in both offices and homes. Instead of the 28.8 kbits/sec or 33.5 kbits/sec that are usually possible under ideal circumstances, which are rare, an ISDN modem delivers reliably from 56 kbits/sec to 128 kbits/sec, depending on circumstances.
Even though ISDN equipment is popular, the fact remains that configuring ISDN modems can be quite tricky and time consuming, especially for the uninitiated. One of the reasons this is so, is that in addition to the normal set of modem set-up parameters in North America there are a variety of ISDN standards. Because there are a number of standards that may be used it is necessary when configuring an ISDN modem to program the standard used by the local switch of the phone company into the modem or adapter device in order for device to work properly
There are three main standards, which are National ISDN, which is more or less the standard ISDN, AT&T ESS5 Custom, and Northern Telecom DMS100 Custom PVC01 or PVC02. The standards pertain in large extent to the data protocol of data packets communicated on the phone line, and the differences in this regard are not critical to the present invention, and are well-known to those with skill in the art, so are not described in detail here. What does happen is that in the various standards the way a phone number is presented in dialing is different. For example, in one standard a number to be dialed may have to be preceded by a pound-sign (#), in another by an asterisk (*), and in another by the letter (N).
Typically a local phone company tries to notify customers and potential customers of the local standard, but due to very large volume and other reasons, the information doesn't always get out to the right people as needed. As a result, there is a lot of guesswork involved for most ordinary folks in configuring an ISDN modem. A typical conventional procedure is presented below.
What is clearly needed is a system that allows a user to plug in a modem and expect it to work (plug-and-play configuration), without having to deal with what type of communication standard the local phone company might be using.